Tool for applying and locking threaded fasteners

ABSTRACT

A fluid-powered tool for applying a threaded fastener on a correspondingly threaded shank to a predetermined tightness and then locking it in place by deforming or swaging the fastener upon the shank to interlock their threads. The tool includes a rotatably driven nut socket, a fluid motor for driving the socket, and a torque responsive shutoff device effective to stop rotation of the socket when a predetermined torque has been reached. The locking or deforming mechanism includes a plurality of reciprocating jaws positioned radially adjacent the nut socket which jaws are movable in a remote position external of the socket to a deforming position extending into the socket. A control means is provided which will cause the jaws to automatically move to their deforming position after the torqueresponsive shutoff device has stopped rotation of the nut and to return the jaws to their remote position so that the tool may be removed.

United States Patent Mar. 7, 1972 Reynolds [54] TOOL FOR APPLYING AND LOCKING THREADED FASTENERS [72] Inventor: Harold C. Reynolds, Athens, Pa.

[73] Assignee: Cooper Industries, Inc., Houston, Tex.

22 Filed: May 18,1970

[21] Appl. No.: 38,168

Primary Examiner-Othell M. Simpson Attorney-Owen & Owen [5 7] ABSTRACT A fluid-powered tool for applying a threaded fastener on a correspondingly threaded shank to a predetermined tightness and then locking it in place by deforming or swaging the fastener upon the shank to interlock their threads. The tool includes a rotatably driven nut socket, a fluid motor for driving the socket, and a torque responsive shutoff device effective to stop rotation of the socket when a predetermined torque has been reached. The locking or deforming mechanism includes a plurality of reciprocating jaws positioned radially adjacent the nut socket which jaws are movable in a remote position external of the socket to a deforming position extending into the socket. A control means is provided which will cause the jaws to automatically move to their deforming position after the torque-responsive shutofi" device has stopped rotation of the nut and to return the jaws to their remote position so that the tool may be removed.

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TOOL FOR APPLYING AND LOCKING THREADED FASTENERS BACKGROUND OF THE INVENTION There are in the prior art many forms of locknuts, lockwashers and combinations for preventing the unintentional loosening or removal of a nut threaded upon a bolt or stud. In most cases, the threads of such devices are deformed during their manufacture or designed so that the nut threads do not perfectly mate or run freely upon the bolt or stud. Such locknuts, which are known in the art as prevailing torque nuts, are satisfactory for many installations but have the disadvantage that their application is slow and requires a high amount of torque during the entire application process, as opposed to a standard nut which can be rapidly applied with a power tool or even by hand.

For this reason, there have been several attempts to provide a system of post-deformation of threaded fasteners which accomplish the same result of locking the joint together against the unintentional loosening or removal but yet permit the joint to be rapidly assembled and brought up tight with a minimum of applied power.

Such post-deformation systems have utilized various means for deforming the threads exposed on the bolt above the nut or have attempted to deform the nut, after its application, by some sort of impact device. Impact devices, such as those shown in U.S. Pat. No. 1,925,714, 2,538,343 and 3,003,378 are designed to deform either the bolt or nut by movement of an impact member of substantial mass in a direction generally parallel to the axis of the bolt. These devices inherently require that the impacting tool have a high amount of mass in order to impart the necessary momentum to the deforming tool to sufficiently deform the nut or bolt so that the mated threads are deformed or swaged together to prevent unintentional rotation. Such systems, particularly for a hand-held tool, are very bulky, noisy and subject to wear and high maintenance costs.

Another impact device is disclosed in U.S. Pat. No. 3,479,714 in which a nut is deformed in a radial direction by impact members positioned adjacent the faces of a hexagonal nut. While a tool of this type has the advantage that a high mass is not required to prevent the unintentional lifting of the tool from the nut, it is limited in application because the impact force for deforming the nut is derived directly from rotational energy used in driving the nut socket. This means that as the nut is impacted and deformed, a certain amount of rotation is present which impedes the desired thread deformation. This device also suffers the drawbacks inherent in such impact devices in that it is relatively slow acting, noisy, and subject to wear of the parts.

In place of the impact type devices of the type described in the above mentioned U.S. Patents, the present invention pro vides a nonimpact type of a mechanism which applies a force to deform the nut which is independent of the rotational movement of the socket tightening the nut. It is a primary object of the present invention to provide a combination nutdriving and nut-locking tool which is powered by relatively low-pressure air and which includes controls which eliminate the disadvantages of impact-type mechanisms. The present invention also contemplates a unique control system which automatically actuates the nut-deforming mechanism when the nut has been driven to a predetermined tightness and rotation of the driving member has been stopped.

SUMMARY OF THE INVENTION The tool of this invention is a combination fluid-powered tool for driving a threaded fastener to a predetermined tightness, shutting off the drive mechanism to stop the drive socket, and then subsequently deforming the nut upon its threaded shank by means of a plurality of jaws which move radially inwardly upon the nut to deform or swage the metal at the thread interface between the nut and the bolt or stud. The deforming jaws are designed with a mechanical advantage so that, in the preferred embodiment, relatively low-pressure air may be used to move the jaws to deform the nut. Other embodiments include a hydraulically operated unit or a camoperated mechanism for actuating the deforming jaws. In each case, the deforming movement of the jaws is automatically actuated in response to the nut reaching a predetermined torque upon its shaft. Other objects and advantages will be apparent from the following detailed description of the preferred embodiments.

DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of the tool of this invention, showing it in driving position upon a threaded fastener;

FIG. 2a is a view in elevation of a typical threaded fastener upon a threaded shank, ready to be applied and then deformed by the tool shown in FIG. 1;

FIG. 2b is a view in elevation similar to FIG. 2a but showing the threaded fastener completely tightened upon the shank and deformed to lock it thereon;

FIG. 3a is a cross-sectional view in elevation of the tool shown in FIG. 1, taken along line 30-311 thereof and shown on an enlarged scale, illustrating the air control system for sensing the torque applied to the fastener and for initiating operation of the nut-deforming unit;

FIG. 3b is a cross-sectional view in elevation of the tool of FIG. 1, taken along line 3b3b of FIG. 1 and shown on an enlarged scale, showing the details of one embodiment of the nut-deforming mechanism of this invention;

FIG. 4 is a cross-sectional view in elevation of the nutdeforming mechanism shown in FIG. 3b, shown on an enlarged scale and showing the mechanism in nut-defonning position;

FIG. 5 is a cross-sectional view of the nut-deforming mechanism shown in FIG. 4, taken along line 55 thereof;

FIG. 6 is a cross-sectional view of a portion of the nutdeforming mechanism in FIG. 4, taken along line 66 thereof;

FIG. 7 is a plan view of one of the nut-deforming levers utilized in the nut-deforming mechanism shown in FIGS. 3b and FIG. 8 is a cross-sectional view of a portion of the nutdeforming mechanism shown in FIG. 4, taken along line 88 thereof, through the nut being acted upon;

FIG. 9 is a schematic view of the air control system used in the tool shown in FIGS. 3a and 3b;

FIG. 10 is a cross-sectional view in elevation of a second embodiment of a nut-deforming mechanism;

FIG. 1 1 is a cross-sectional view of a portion of the embodiment shown in FIG. 10, taken along line ll--ll thereof;

FIG. 12 is a cross-sectional view in elevation of yet another embodiment of a nut-deforming mechanism which utilizes a cam to provide the deforming force;

FIG. 13 is a cross-sectional view of the embodiment of FIG. 12, taken along line 13-13 thereof;

FIG. 14 is a cross-sectional view of the embodiment of FIG. 12, taken along line 14-14 thereof; and

FIG. 15 is a cross-sectional view of the embodiment of FIG. 12, taken along line l5l5 thereof and showing the shape of the cam.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1, 3a and 3b, the nut applying and locking tool of this invention is shown as including a fluidoperated air tool having an elongate, generally cylindrical body 10 and a nut-deforming unit 11 extending at right angles. For certain applications, it may be desirable to have the body 10 and defonning unit 11 coaxial. The air tool is essentially of conventional design with the exception of the fluid control system which is shown in FIGS. 3a and 9. The remainder of the air tool, which need not be described in detail, includes a conventional rotary air motor 12 which, as shown in FIGS. 1 and 3a, is supplied with air under pressure from a supply line 13 connected to an air passage 14 which leads to one side of a manually operated shutoff valve 15. When a trigger 16 on the outside of the body is depressed by an operator, the shutoff valve is moved downwardly against its return spring 17 so that air may pass into the valve chamber 18, through passage 19, across the central portion of a spool valve 20, whose function will be subsequently explained, then into an air passage which leads to the air motor 12.

The air motor 12 is of conventional design and, as best seen in FIG. 3b, has its rotor connected through convention reduction gears 20a to a spindle 21 by a splined sleeve 22. Extending at right angles from the body 10 of the air tool is a cylindrical end 23 which journals for rotation a coaxial, hollow drive shaft 24 positioned within the cylindrical end 23 by suitable bearings 25 and 26. A bevel gear 27 is splined or otherwise secured to the drive shaft 24 and engages the beveled teeth 28 on the end of the spindle 21 so that rotation of the air motor 12 and spindle 21 will turn the drive shaft 24. The lower end of the drive shaft 24, as also seen in FIG, 4, terminates in the threaded connector 29 to which is secured the deforming unit 11.

Referring now to FIGS. 3b and 4, the deforming unit 11 includes a hollow cylindrical housing 30 which is closed at its upper end with the exception of a coaxial threaded opening which is designed to be screwed upon the threaded connector 29 extending from the end 23 of the tool 10. The external boss 31 surrounding the threaded opening at the upper end of the housing 30 has an O-ring seal or other means for making this connection airtight.

The lower end of the cylindrical housing 30 is closed by an end cap 32 secured thereon by a retainer ring 33 which is threaded upon external threads on the lower end of the housing 30. It will be obvious that the entire nut-deforming mechanism to be subsequently described may be inspected and repaired by removal of the retainer ring 33. Placed within the end cap 32, as best seen in FIG. 8, is a tension ring 34 whose outer periphery fits loosely within the internal bore of the end cap 32 and which has an inner opening of a generally triangular shape, as indicated by reference 35. The tension ring 34 is positioned for slight axial movement and is biased upwardly by one or more springs 35a against the lower surface 35b of a socket member 36. The socket member 36 is placed within the inner bore 35 of the tension ring 34 and has a generally triangular outer periphery which fits within the tension ring 34. Extending upwardly into the bottom of the socket member 36, as best seen in FIG. 4, is a generally hexagonal socket formed by three faces 37-39, as indicated in FIG. 8, alternately positioned between three radially extending slots 40-42. The slots 40-42 extend upwardly through the entire height of the socket member 36, as seen in FIG. 4, and the socket member 36 extends upwardly above the tension ring 34 and radially outwardly to form a circular land 43 which is engaged between the housing 30 and the end cap 32 and held in place by the retainer ring 33.

The nut-deforming mechanism consists of three elongate levers 44, one of which is shown in FIG. 7. These levers 44 are positioned within the housing 30 with their lower ends placed within the slots 40-42 which, as shown in FIG. 8, extend radially through the lower portion of the socket member 36. As seen in FIG. 7, each of the levers 44 has, at its lower end, a deforming punch or pin 45 and, at its upper end, a roller 46 journaled on an axis generally normal to the axis of the punch 45. As seen in FIGS. 3b and 4, the outer side of the levers 44 at the lower end has a generally arcuate surface 47 which bears upon the flat inner surface of the tension ring 34. As seen in FIGS. 4 and 8, the levers 44 are positioned within the slots 40-42 of the socket member 36 so that the nut deforming punch 45 extends radially inwardly towards alternate faces of a nut N which would be positioned within the socket member 36.

An axially movable air piston 48 is slidably positioned within the housing 30 for movement from an upper position shown in FIG. 3b to a lower position shown in FIG. 4. A compression spring 49 below the piston 48 urges it towards its upper position by bearing against an internal ridge 50 within the piston 48 and upon a raised surface 50a above the land 43 which is part of the socket member 36. Coaxially secured within the piston 48 is a conical cam 51 which extends downwardly from the upper end of the piston 48 towards the end cap 32. As seen in FIG. 4, a central bore 52 in the upper portion of the socket member 36 is provided for clearance for the tapered cam 51 when the piston 48 is in its lowermost position. An adjustable stop for the stroke of the tapered cam 51 is provided by a setscrew 52a which may be turned by a tool inserted through a hole 52b in the socket member 36 as seen in FIG. 4.

The three deforming levers 44 have their upper ends and rollers 46 positioned about the periphery of and in contact with the tapered cam 51 so that the downward movement of the piston 48 and tapered cam 51 will cause a gradual radially outward movement of the rollers 46 and upper ends of the levers 44. The levers 44 are urged in the position shown in FIG. 3b by a surrounding garter type expansion spring 53 which has a force sufiicient to return the lever arms 44 to the position of FIG. 3b when the piston 48 and tapered cam 51 is at its upper position.

Operation of the deforming device thus far described is briefly as follows. With the piston 48 and tapered cam 51 in the upper position as shown in FIG. 3b, the garter spring 53 holds the upper ends of the lever arms 44 radially inward, as shown, so that the lower ends of the lever arms 44 and their deforming punches 45 are positioned radially outwardly away from the socket in the socket member 36. In this position, the tool may be placed upon a conventional hex nut N, such as that shown in FIG. 2a. By actuation of the air motor 12, as previously described, the entire deforming tool within the housing 30 will be turned by the drive shaft 24 to tighten the nut N upon its bolt. When the nut N has reached a predetermined torque, the control mechanism, to be subsequently described, stops rotation of the housing 30 and nut N, and then causes air under pressure to be admitted to the housing 30 in a chamber 54 above the piston 48. This air pressure, acting upon substantially the entire upper surface of the piston 48, causes it to move downwardly against the compression spring 49 towards the lower position shown in FIG. 4. As downward movement progresses, the tapered cam 51 bears against the rollers 46 on the lever arms 44 and forces them radially outwardly against the garter spring 53. As the upper ends of the lever arms 44 move radially outwardly, the arcuate surface 47 on the external side of their lower ends rocks upon the interior surface of the tension ring 34, as best seen in FIGS. 4 and 8, so that the lowermost ends of the levers 44 are moved radially inwardly into the socket in the socket member 36. As the upper end of the lever 44 continues to move radially outwardly, the arcuate surface 47 rocks on the ring 34 without sliding thereon and moves the ring 34 downwardly against its spring 35:: so that the punch 45 moves only radially inwardly without any substantial component of axial movement. As this movement continues, the deforming punch 45 strikes the alternate faces of the nut N and swage it radially inwardly in an amount sufficient to deform the nut threads against the bolt threads to lock the nut in place. The finally deformed nut N appears as that shown in FIG. 2b, with the indentations 55 made by the defonning punches 45 on three alternate nut faces.

There are several advantages inherent in the operation of the device described thus far. Firstly, the three lever arms 44 are alternately positioned around the face of the nut being deformed so that there are no unopposed lateral forces exerted upon or within the tool. Secondly, the deforming force from the air pressure in the chamber 54 does not depend upon rotational energy used to drive the nut and does not require an impact member of a substantial mass to create such a force. Thirdly, the lever arms 44 are designed with a mechanical advantage so that a relatively low fluid pressure in the chamber 54 results in a substantially high deforming force upon the nut faces. This mechanical advantage is due to the gradual slope of the tapered cam 51 and also the difference in distances between the arcuate surface 47 and the deforming punch 45 and the roller 46. Also, as previously explained, the movement of the ring 34 as the surface 47 rocks thereon eliminates substantially all sliding friction between these parts. It should be noted in addition that release of the deforming punches 45 from the nut N is automatic as soon as the air pressure in the chamber 54 above the piston 48 has been vented because the compression spring 49 returns the piston 48 to its upper position and the garter spring 53 returns the levers 44 to their initial position so that the tool may be freely removed therefrom.

It should be noted that the parts most subject to wear in the device thus far described will be the deforming punches 45, rollers 46 and tapered cam 51, each of which is readily replaceable by removal of the retainer ring 33. In addition, the mechanical advantage of the device may be varied by changing the slope of the tapered cam 51, which is readily removable from its coaxial position upon the piston by removal of a securing screw 56, so that the device may be modified to accommodate bolts of various hardness or size.

The air supplied to the chamber 54 above the piston 48, hereinafter referred to as the deforming air pressure, is supplied through the central passage in the drive shaft 24 which is connected to an angular fitting, as shown in FIGS. 1 and 3b, leading to an external air line 57 which returns to the control valve portion of the air tool as shown in FIG. 3a. The automatic air control system incorporated in the tool of this invention can be best understood with reference to FIG. 9 which is a schematic diagram thereof. As shown in FIG. 9, the fluid supply line 13 is connected to the manual shutoff valve whose outlet passage 19 leads to the sensing spool valve 20. The air passage from the spool valve 20, designated by reference numeral 58, leads to the air motor '12. An internal control port 59 connects the line 58 to an air accumulator chamber 60 below the spool valve which, when sufficiently pressurized, will move the spool valve 20 upwardly against its spring 61. A second spool valve 62 has one end of its cylinder 63 connected to a branch line 58a of the line 58 and its other end connected to the passage 19 by a line 19a. The external air line 57 from the deforming unit connects to an intermediate opening or port 64 as shown. This port 64 is vented when the second spool valve 62 is held in its right-hand position by its spring 65.

Operation of this schematically shown system is as follows. With the spool valves 20 and 62 in their starting positions as shown, when the operator has placed the tool on a nut for tightening, he manually opens the valve 15 by the handle 16 which admits air under pressure to the air motor 12 through the lines 19 and 58. As the nut approaches its ultimate tightness, the back pressure in the line 58 from the air motor 12 increases and is communicated to the accumulator chamber 60 through the control port 59. When this pressure reaches a predetermined value, which is proportional to the torque resistance of the nut, the pressure build up in the chamber 60 causes the spool valve 20 to move upwardly against its spring 61. As soon as the lower land 66 of the spool valve 20 moves up slightly, it opens a holding port 67 which connects airflow from line 19 to the entire area below the spool valve 20 to quickly raise this valve to its upper position where it closes off airflow to the line 58. This causes the air motor 12 to stop. Simultaneously, as the air pressure in line 58a is reduced, the second spool valve 62 is caused to move to the left by air pressure in line 19a. When this happens, the port 64 leading to the external line 57 is connected to the supply air in line 19a. This causes the deforming unit to be actuated as previously described to deform the nut upon its bolt. With the nut-deforming unit actuated, the system remains in this condition until the operator manually closes the air supply valve 15 by releasing the trigger 16, at which time the spool valves 20 and 62 will return to their positions shown and the pressure in the external line 57 will be vented through the stem of the spool valve 62 to the atmosphere through a vent 68 which will cause the deforming unit to return to its previous or open position. At this time, the unit is again ready to be placed upon a second nut for turning and subsequent deformation.

It will be obvious from the foregoing description that the size of the various supply passages and the strength of the spring 61 will control the point at which the pneumatic control system stops rotation of the nut and starts actuation of the deforming unit. Thus a simple external adjusting mechanism in the mounting of the control spool 20 and its spring 61 can be used to vary the output torque at which the control system stops nut rotation and starts nut deformation.

FIGS. 10 and 11 illustrate another embodiment of the nutdeforming unit which is essentially similar to that shown in FIG. 4 but in which the mechanism for moving the deforming levers 44 is different. In this embodiment, wherein similar parts are designated by similar reference numerals, the housing 30 which contains the deforming unit mechanism is again secured to the threaded end of the drive shaft 24 so that the entire unit turns with the drive shaft 24 to tighten the nut. Three deforming levers 44 are again positioned about the axis of the unit with their lower ends and deforming punches 45 alternately spaced about the faces of the nut. Adjacent the upper ends of the deforming levers 44 are three radially movable pistons 69-71 which, as best seen in FIG. 11, are positioned for radial reciprocation within three piston cylinders formed by a wall structure 72 which is an integral part of the upper portion of the socket member 36. The wall structure 72 provides a central opening 73 which is in communication with the fluid passage extending through the drive shaft 24. The inner faces of each of the pistons 69-71 are exposed to the central opening 73 and the outer faces of the pistons 69-71 are provided with slots to receive the upper ends of the lever arms 44.

When fluid under pressure is admitted to the central opening 73, the pistons 69-71 are forced radially outwardly, with equal speed and force, to move the upper ends of the lever arms 44 outwardly, pivoting the lower ends and deforming punches 45 radially inwardly to deform the nut, as was previously explained in detail with reference to the FIG. 4 embodiment. Once the fluid pressure in the central opening 73 is relieved, the circumferential spring 53 returns the lever arms 44 to their previous position to remove the deforming punches 45 from the nut.

In this embodiment of FIGS. 10 and 11, because the exposed faces of the pistons 69-7l have relatively small area in relation to the exposed face of the large piston 48 in the embodiment of FIG. 4, higher air prewure would be required for an equivalent deforming force. While such air pressures are feasible for smaller nuts of relative soft material, this embodiment will require utilization of high-pressure hydraulic fluid as the source of deforming force when large nuts of harder material are to be applied. It will be apparent to those skilled in the art that a control system similar to that shown schematically in FIG. 9 may be used with either air or hydraulic fluid as the deforming force in this embodiment, with the obvious substitution of a pneumatically controlled hydraulic control valve to control the hydraulic fluid pressure to the deforming unit. This embodiment also has many of the advantages inherent to the embodiment of FIG. 4 in that it does not require a substantial mass to provide impact to deform the nut and is subject to automatic control as previously explained.

Still another embodiment is shown in FIGS. 12-15 in which like parts are given similar reference numerals. In this embodiment, referring particularly to FIG. 12, the actuating force for the nut deforming levers 44 is provided by a three-lobe cam 74 which is splined or clutched to the end of the drive shaft 24. The upper ends of the deforming levers 44 are each provided with a roller bearing 75 whose axis is substantially parallel to that of the major axis of the lever 44. As best seen in FIG. 15, with the upper arms of the levers 44 and their roller bearings 75 in a radially inward position, they lie positioned against three arcuate depressions machined in the cam so that the lower ends of the levers 44 and their deforming punches 45 are withdrawn from the nut as shown in FIG. 12. When the cam 74 turns relative to the remainder of the deforming unit, clockwise as shown in FIG. 15, the rollers 75 ride outwardly on the lobes of the cam to move the lower ends of the levers 44 inwardly.

The torque control device for this cam driven embodiment includes a pneumatically shifted clutch jaw 78 keyed to the drive shaft 24 above the cam 74 and a fixed clutch ring 78a which is secured relative to the socket member 36. The piston 78b integral with the clutch jaw 78 is positioned within a central cavity of a cylinder cap 79 and will move from an upper position shown in FIG. 12, to a lower position along the axis of the drive shaft 24. Air under pressure is connected to the cavity above the piston 78b by radial ports 80 extending from the central air passage in the drive shaft 24.

The clutch jaw 78 is biased towards its upper position by clutch springs 81. In the absence of air pressure above the clutch piston 78b, it remains in its upper position at which position two clutch dogs 82, as seen in FIG. 14, mesh with correspondingly shaped drive slots 83 in the clutch ring 78a. The cylinder cap 79 and clutch ring 78a are directly secured to the socket member 36 so that the entire unit is directly driven by the drive shaft 24 with the clutchjaw 78 in this upper position.

When fluid pressure is admitted above the clutch piston 78b through the radial ports 80, the clutch jaw 78 moves to its lower position to release the dogs 82 from their slots 83. In this position, the clutch dogs 82 move below the portion of the clutch ring 78a containing the drive slots 83 and now lie within an open segment 84 in the clutch ring 78a, as seen in FIG. 13. This disengages the drive connection between the drive shaft 24, the upper part of the clutch ring 78a and socket member 36. However, the cam 74, which is directly connected to the drive shaft 24, now turns relative to the nut socket 36 and nut so that the levers 44 are moved into deforming engagement.

As shown in FIG. 13, the clutch dogs 82 are free to move relative to the nut socket 36 while the cam 74 is being driven alone for about 90 of rotation, at which time they strike stops 85 secured to the lower portion of the clutch ring 78a below the level of the slots 83 shown in FIG. 14. When the dogs 82 reach these stops 85, the cam 74 has rotated relative to the socket 36 and levers 44 to a position at which the cam lobes have moved the levers 44 to their fully closed position to defonn the nut as previously described.

A pneumatic torque-sensing and control system similar to that schematically shown in FIG. 9 can be used with this embodiment of FIGS. l17 to sense the point at which the desired torque on the nut has been attained, then to reduce this torque in order to allow the clutch 78 to be shifted by air introduced through the radial ports 80, and then to provide sufiicient torque to rotate the cam 74 in order to deform the nut. Upon release of air pressure, caused by the operators release of the trigger 16, the clutch moves to its upper position, the cam 74 returns to the position of FIG. 15, and the levers 44 and their punches 45 are returned to their open, retracted position by the circumferential spring 53.

It will be obvious to those skilled in the art that each of the nut-deforming embodiments described in detail above, when used with the basic air-driven tool, provide a tool for applying and deforming nuts which is free of the disadvantages inherent in prior an impact mechanisms used for this purpose and also provide a number of other advantageous features. Through use of the pneumatic control system, the maximum torque may be readily set through adjustment of the compression of the spring 61 so that the tool may be adapted for a plurality of uses without extensive modification. In addition, it will be apparent to those skilled in the art that other torque responsive clutch mechanisms, mechanical or electrical, can be used as a transducer mechanism to stop rotation of the tool and to initiate a control signal to actuate deforming air pressure to subsequently deform the nut.

Other objects and advantages of the invention will be apparent to those skilled in the art and may be made without departing from the scope of the appended claims.

I claim:

l. A tool for applying and locking threaded fasteners comprising, in combination, a rotatably mounted wrench socket adapted to engage and rotate a threaded nut relative to a bolt, drive means powered by a source of fluid pressure for rotating said socket about an axis of rotation, control means responsive to the torque encountered by said drive means and effective to shut off said drive means and stop rotation of said socket when said encountered torque reaches a predetermined value, said control means comprising a pressure-sensitive fluid shutofl' valve responsive to back pressure from said drive means, means for deforming such nut in a direction substantially normal to said axis of rotation, said deforming means including at least one lever arm having an outer end positioned radially adjacent said socket member and movable from a first position outside of said socket through a passage in said socket member to a second position within said socket member, a punch on said outer end of said lever arm extending radially into said socket when said lever arm is in said second position, power means for moving said lever arm between said first and second positions, and means for causing said power means to move said lever arm into said second position to embed said punch into such nut after said nut has been applied with said predetermined torque.

2. The tool defined in claim 1 wherein said means for causing said power means to move said lever arm is a sensing mechanism responsive to said control means.

3. The tool defined in claim 1 wherein said nut-deforming means includes a plurality of lever arms equally spaced around the periphery of said socket, each of said lever anns movable from said first to said second position, and whereas said power means is adapted to move said lever arms in unison from said first to said second positions.

4. The tool defined in claim 1 wherein said socket and deforming means are contained within an annular housing, said housing having an inner end secured to said drive means for rotation therewith 'with said socket secured coaxially in the outer end of said housing, said lever arm'extending generally axially within said housing with said outer end radially outward of and adjacent to said socket and the inner end thereof extending toward said inner end of said housing.

5. The tool defined in claim 4 wherein said annular housing contains a fluid-actuated piston movable from a remote position adjacent said inner end of said housing to an extended position, means for supplying fluid under pressure to the space between said piston and said inner end of said housing, bias means urging said piston toward its remote position, and a cam moved by said piston and positioned to engage said lever arm when said piston moves from said remote position to said extended position to force said lever arm to its said second position to deform such nut upon admission of fluid pressure to said space between said piston and said inner end of said housing.

6. The tool defined in claim 5 wherein said cam is a conically tapered member having its larger end coaxially secured to said piston within said housing and extending from said piston towards said outer end of housing and said lever arm is positioned with its inner end adjacent the smaller end of said tapered member when said piston is in said remote position whereby, when said piston moves to its said extended position,

said tapered member forces said inner end of said lever arm radially outwardly to cause said outer end and said punch to move radially inwardly into said socket.

7. The tool defined by claim 5 which further includes a tension ring coaxially secured within said housing circumjacent the outer end of said lever arm with the interior surface of said tension ring in contact with the outer surface of said lever arm whereby movement of said piston to its extended position will rock said lever arm upon said tension ring towards said second position of said lever arm.

8. A tool for applying and locking a threaded nut to a bolt comprising a driven nut socket, a fluid motor operably connected to said nut socket to rotate a nut positioned therein about an axis, control means responsive to torque resistance encountered by such nut effective to shut off fluid supply to said motor and thereby stop rotation of said socket and nut when said encountered torque reaches a predetermined value, said control means comprising a pressure-responsive fluid shutoff valve responsive to back pressure from said fluid motor and means for deforming said nut upon its bolt, said deforming means including a plurality of jaws equally spaced about said socket and adapted to move from an open position external of said socket to a closed position extending radially into said socket, fluid-actuated drive means operably connected to said jaws to move said jaws from their open to their closed position, bias means urging said jaws to their open position, and sensing means responsive to said control means and effective to cause said fluid-actuated jaw drive means to close said jaws when said control means has shut off power to said socket.

9. The tool of claim 8 wherein said sensing means is a second pressure-responsive valve in the fluid supply line to said fluid-actuated jaw drive means which will open said fluid supply line to said fluid-actuated jaw drive means when said first pressure-responsive valve closes said fluid supply line to said fluid motor.

10. The tool of claim 8 wherein said nut socket and jaws are secured within an annular housing adapted to rotate with said socket and wherein said fluid-actuated drive means for said jaws is a fluid pressure-responsive piston secured within said housing and movable from a remote position away from said jaws to an extended position at which said jaws are forced to their said closed position.

11. The tool defined in claim 8 wherein said fluid motor is an air motor and said control means comprises a pressure-sensitive air shutoff valve responsive to back pressure from said motor.

12. The tool of claim 10 wherein said piston moves a cam positioned to engage said jaws and to force them towards their said closed position as said piston moves towards its said extended position.

13. The tool of claim 8 wherein said plurality ofjaws are a plurality of elongate lever arms spaced about said nut socket and extending generally parallel to the axis of rotation of said nut, each of said lever arms having a lower end radially adjacent said nut socket and an upper end spaced therefrom and wherein said fluid-actuated drive means for moving said jaws includes a fluid piston movable from an upper remote position to a lower extended position and a cam positioned to engage said upper ends of said lever arms and to force them radially outwardly as said piston moves to its said lower position, thereby causing said lower ends to move radially inwardly about said nut socket.

14. The tool of claim 13 which further includes a tension ring positioned circumjacent the lower ends of said lever arms but above said socket whereby radial outward movement of the upper ends thereof causes said lever to rock upon said tension ring to move its said lower ends radially inwardly towards said socket.

15. The tool of claim 14 wherein the distance between the lower ends of said lever arms and their rocking point on ,said tension ring is substantially less than the distance between said rocking point and said upper end of said lever arm.

16. A tool for locking a threaded nut to a bolt comprising a nut socket, a plurality of nut-deforming punches equally spaced about said socket and adapted to move from an open position external of said socket to a closed position extending radially into said socket, a plurality of lever arms spaced about said socket and extending generally parallel to the axis of rotation of said nut, each of said lever arms having a lower end supporting one of said punches radially adjacent said socket and an upper end spaced therefrom, a fluid-responsive means for moving said punches from said open to closed position including a fluid piston movable from a remote position to an extended position, a tension ring positioned circumjacent the lower ends of said lever arms but above said socket whereby the radial outward movement of the upper ends thereof causes said arms to rock upon said tension ring to move their lower ends and thus said punches radially inwardly towards said closed position, and means carried by said piston for forcing the upper ends of said lever arms outwardly as said piston moves from said remote to said extended position.

17. The tool of claim 16 wherein said means carried by said piston is a tapered cam coaxially secured thereto and extending from said piston towards said socket with the narrow portion thereof adjacent said upper ends of said lever arms when said piston is in its said remote position whereby movement of said piston towards its said extended position will cause said cam to force said upper ends of said lever arms radially outwardly.

18. The tool of claim 16 wherein the outer surface of said lever arms adjacent said tension ring is arcuate shaped to facilitate rocking thereon.

19. The tool of claim 16 wherein said tension ring is secured relative to said socket by bias means which permit limited axial movement towards said nut socket as said punches move from open to closed position.

20. A tool for applying and locking a threaded nut to a bolt comprising a driven nut socket, a fluid motor operably connected to said nut socket to rotate a nut positioned therein about an axis, control means responsive to torque resistance encountered by such nut effective to shut off fluid supply to said motor and thereby stop rotation of said socket and nut when said encountered torque reaches a predeten'nined value, and means for deforming said nut upon its bolt, said deforming means including a plurality of jaws equally spaced about said socket and adapted to move from an open position external of said socket to a closed position extending radially into said socket, fluid-actuated drive means operably connected to said jaws to move said jaws from their open to their closed position, said fluid-actuated drive means including a plurality of fluid pistons positioned in operative relation to said jaws and responsive to a common source of fluid pressure whereby said pistons will move said jaws in unison, and sensing means responsive to such control means and effective to cause said fluid-actuated drive means to move said pistons to close said jaws when said control means has shut off power to said socket.

21. The tool of claim 20 wherein each one of said plurality of fluid pistons are equally spaced apart and opposite one of said jaws on radially extending axes whereby the application of fluid pressure thereto will move said pistons radially outwardly to force the opposed portion of said jaws radially outwardly.

22. The tool of claim 21 wherein said jaws are spring biased towards their said open position whereby upon release of said fluid pressure upon said pistons, said jaws are returned to their said open position and said pistons are moved radially inwardly.

23. A tool for applying and looking a threaded nut to a bolt comprising a driven nut socket, a fluid motor operably connected to said nut socket to rotate said nut socket and thus a nut positioned therein about an axis, a nut-defonning mechanism rotatable with said nut socket and including a plurality of jaws equally spaced about said socket and movable from an open position external of said socket to a closed position extending radially into said socket, a deforming mechanism drive means operably connected to said fluid motor and effective to move said plurality of jaws from their said open to their said closed position, said drive means including a cam driven by said fluid motor, said cam having a plurality of alternate lobes and depremions in driving engagement with said plurality of jaws such that rotation of said cam relative to said jaws will cause said cam lobes to move said jaws from their said open to closed positions and a control mechanism responsive to the torque upon said nut and effective to stop rotation thereof when said nut reaches a predetermined torque and to initiate relative rotation of said cam relative to said jaws to move said jaws to their said closed positions.

24. The tool of claim 23 wherein said jaws comprise an elongate lever extending generally parallel to the axis of rotation of said nut socket with a lower end radially adjacent said nut socket and an upper end radially adjacent said cam and which includes a bias spring urging the upper ends of said elongate levers toward a radially inward position against said cam.

25. The tool of claim 24 which further includes a tension ring circumjacent said nut socket and the lower ends of said elongate levers with the interior surface of said tension ring in contact with the outer surface of each of said lever arms whereby movement of the upper ends of said elongate lever arms in a radially outward direction will rock said lever arms upon said tension ring to move the lower ends thereof radially inwardly towards their said closed position.

26. The tool of claim 23 wherein said control mechanism includes a fluid-operated clutch for selectively disengaging said fluid motor with said nut socket and wherein said cam remains directly connected to said fluid motor.

27. The tool of claim 26 wherein said clutch includes a movable clutch jaw driven by said fluid motor on an axis paral-. lel with the axis of said nut and cam and movable along said axis from a first position in driving engagement with said nut socket to a second position free of said socket whereby said cam may be driven independently of said socket.

28. The tool of claim 27 which further includes a fluid control means responsive to torque resistance encountered by said motor driving said socket and effective to shift said clutch plate from its said first to its said second position when said motor encounters a predetermined torque level, thereby stopping rotation of said nut socket and initiating relative rotation of said cam.

4 e a a e 

1. A tool for applying and locking threaded fasteners comprising, in combination, a rotatably mounted wrench socket adapted to engage and rotate a threaded nut relative to a bolt, drive means powered by a source of fluid pressure for rotating said socket about an axis of rotation, control means responsive to the torque encountered by said drive means and effective to shut off said drive means and stop rotation of said socket when said encountered torque reaches a predetermined value, said control means comprising a pressure-sensitive fluid shutoff valve responsive to back pressure from said drive means, means for deforming such nut in a direction substantially normal to said axis of rotation, said deforming means including at least one lever arm having an outer end positioned radially adjacent said socket member and movable from a first position outside Of said socket through a passage in said socket member to a second position within said socket member, a punch on said outer end of said lever arm extending radially into said socket when said lever arm is in said second position, power means for moving said lever arm between said first and second positions, and means for causing said power means to move said lever arm into said second position to embed said punch into such nut after said nut has been applied with said predetermined torque.
 2. The tool defined in claim 1 wherein said means for causing said power means to move said lever arm is a sensing mechanism responsive to said control means.
 3. The tool defined in claim 1 wherein said nut-deforming means includes a plurality of lever arms equally spaced around the periphery of said socket, each of said lever arms movable from said first to said second position, and whereas said power means is adapted to move said lever arms in unison from said first to said second positions.
 4. The tool defined in claim 1 wherein said socket and deforming means are contained within an annular housing, said housing having an inner end secured to said drive means for rotation therewith with said socket secured coaxially in the outer end of said housing, said lever arm extending generally axially within said housing with said outer end radially outward of and adjacent to said socket and the inner end thereof extending toward said inner end of said housing.
 5. The tool defined in claim 4 wherein said annular housing contains a fluid-actuated piston movable from a remote position adjacent said inner end of said housing to an extended position, means for supplying fluid under pressure to the space between said piston and said inner end of said housing, bias means urging said piston toward its remote position, and a cam moved by said piston and positioned to engage said lever arm when said piston moves from said remote position to said extended position to force said lever arm to its said second position to deform such nut upon admission of fluid pressure to said space between said piston and said inner end of said housing.
 6. The tool defined in claim 5 wherein said cam is a conically tapered member having its larger end coaxially secured to said piston within said housing and extending from said piston towards said outer end of housing and said lever arm is positioned with its inner end adjacent the smaller end of said tapered member when said piston is in said remote position whereby, when said piston moves to its said extended position, said tapered member forces said inner end of said lever arm radially outwardly to cause said outer end and said punch to move radially inwardly into said socket.
 7. The tool defined by claim 5 which further includes a tension ring coaxially secured within said housing circumjacent the outer end of said lever arm with the interior surface of said tension ring in contact with the outer surface of said lever arm whereby movement of said piston to its extended position will rock said lever arm upon said tension ring towards said second position of said lever arm.
 8. A tool for applying and locking a threaded nut to a bolt comprising a driven nut socket, a fluid motor operably connected to said nut socket to rotate a nut positioned therein about an axis, control means responsive to torque resistance encountered by such nut effective to shut off fluid supply to said motor and thereby stop rotation of said socket and nut when said encountered torque reaches a predetermined value, said control means comprising a pressure-responsive fluid shutoff valve responsive to back pressure from said fluid motor and means for deforming said nut upon its bolt, said deforming means including a plurality of jaws equally spaced about said socket and adapted to move from an open position external of said socket to a closed position extending radially into said socket, fluid-actuated drive means operably connected to said jaws to move said jaws from their open to their closed position, bias means urging said jaws to their open position, and sensing means responsive to said control means and effective to cause said fluid-actuated jaw drive means to close said jaws when said control means has shut off power to said socket.
 9. The tool of claim 8 wherein said sensing means is a second pressure-responsive valve in the fluid supply line to said fluid-actuated jaw drive means which will open said fluid supply line to said fluid-actuated jaw drive means when said first pressure-responsive valve closes said fluid supply line to said fluid motor.
 10. The tool of claim 8 wherein said nut socket and jaws are secured within an annular housing adapted to rotate with said socket and wherein said fluid-actuated drive means for said jaws is a fluid pressure-responsive piston secured within said housing and movable from a remote position away from said jaws to an extended position at which said jaws are forced to their said closed position.
 11. The tool defined in claim 8 wherein said fluid motor is an air motor and said control means comprises a pressure-sensitive air shutoff valve responsive to back pressure from said motor.
 12. The tool of claim 10 wherein said piston moves a cam positioned to engage said jaws and to force them towards their said closed position as said piston moves towards its said extended position.
 13. The tool of claim 8 wherein said plurality of jaws are a plurality of elongate lever arms spaced about said nut socket and extending generally parallel to the axis of rotation of said nut, each of said lever arms having a lower end radially adjacent said nut socket and an upper end spaced therefrom and wherein said fluid-actuated drive means for moving said jaws includes a fluid piston movable from an upper remote position to a lower extended position and a cam positioned to engage said upper ends of said lever arms and to force them radially outwardly as said piston moves to its said lower position, thereby causing said lower ends to move radially inwardly about said nut socket.
 14. The tool of claim 13 which further includes a tension ring positioned circumjacent the lower ends of said lever arms but above said socket whereby radial outward movement of the upper ends thereof causes said lever to rock upon said tension ring to move its said lower ends radially inwardly towards said socket.
 15. The tool of claim 14 wherein the distance between the lower ends of said lever arms and their rocking point on said tension ring is substantially less than the distance between said rocking point and said upper end of said lever arm.
 16. A tool for locking a threaded nut to a bolt comprising a nut socket, a plurality of nut-deforming punches equally spaced about said socket and adapted to move from an open position external of said socket to a closed position extending radially into said socket, a plurality of lever arms spaced about said socket and extending generally parallel to the axis of rotation of said nut, each of said lever arms having a lower end supporting one of said punches radially adjacent said socket and an upper end spaced therefrom, a fluid-responsive means for moving said punches from said open to closed position including a fluid piston movable from a remote position to an extended position, a tension ring positioned circumjacent the lower ends of said lever arms but above said socket whereby the radial outward movement of the upper ends thereof causes said arms to rock upon said tension ring to move their lower ends and thus said punches radially inwardly towards said closed position, and means carried by said piston for forcing the upper ends of said lever arms outwardly as said piston moves from said remote to said extended position.
 17. The tool of claim 16 wherein said means carried by said piston is a tapered cam coaxially secured thereto and extending from said piston towards said socket with the narrow portion thereof adjacent said upper ends of said lever arms when said piston is in its said remote position whereby movement of said piston towards its said extended position will cause said cam to force said upper ends of said lever arms radially outwardly.
 18. The tool of claim 16 wherein the outer surface of said lever arms adjacent said tension ring is arcuate shaped to facilitate rocking thereon.
 19. The tool of claim 16 wherein said tension ring is secured relative to said socket by bias means which permit limited axial movement towards said nut socket as said punches move from open to closed position.
 20. A tool for applying and locking a threaded nut to a bolt comprising a driven nut socket, a fluid motor operably connected to said nut socket to rotate a nut positioned therein about an axis, control means responsive to torque resistance encountered by such nut effective to shut off fluid supply to said motor and thereby stop rotation of said socket and nut when said encountered torque reaches a predetermined value, and means for deforming said nut upon its bolt, said deforming means including a plurality of jaws equally spaced about said socket and adapted to move from an open position external of said socket to a closed position extending radially into said socket, fluid-actuated drive means operably connected to said jaws to move said jaws from their open to their closed position, said fluid-actuated drive means including a plurality of fluid pistons positioned in operative relation to said jaws and responsive to a common source of fluid pressure whereby said pistons will move said jaws in unison, and sensing means responsive to such control means and effective to cause said fluid-actuated drive means to move said pistons to close said jaws when said control means has shut off power to said socket.
 21. The tool of claim 20 wherein each one of said plurality of fluid pistons are equally spaced apart and opposite one of said jaws on radially extending axes whereby the application of fluid pressure thereto will move said pistons radially outwardly to force the opposed portion of said jaws radially outwardly.
 22. The tool of claim 21 wherein said jaws are spring biased towards their said open position whereby upon release of said fluid pressure upon said pistons, said jaws are returned to their said open position and said pistons are moved radially inwardly.
 23. A tool for applying and locking a threaded nut to a bolt comprising a driven nut socket, a fluid motor operably connected to said nut socket to rotate said nut socket and thus a nut positioned therein about an axis, a nut-deforming mechanism rotatable with said nut socket and including a plurality of jaws equally spaced about said socket and movable from an open position external of said socket to a closed position extending radially into said socket, a deforming mechanism drive means operably connected to said fluid motor and effective to move said plurality of jaws from their said open to their said closed position, said drive means including a cam driven by said fluid motor, said cam having a plurality of alternate lobes and depressions in driving engagement with said plurality of jaws such that rotation of said cam relative to said jaws will cause said cam lobes to move said jaws from their said open to closed positions and a control mechanism responsive to the torque upon said nut and effective to stop rotation thereof when said nut reaches a predetermined torque and to initiate relative rotation of said cam relative to said jaws to move said jaws to their said closed positions.
 24. The tool of claim 23 wherein said jaws comprise an elongate lever extending generally parallel to the axis of rotation of said nut socket with a lower end radially adjacent said nut socket and an upper end radially adjacent said cam and which includes a bias spring urging the upper ends of said elongate levers toward a radially inward position against said cam.
 25. The tool of claim 24 which further includes a tension ring circumjacent said nut socket and the lower ends of said elongaTe levers with the interior surface of said tension ring in contact with the outer surface of each of said lever arms whereby movement of the upper ends of said elongate lever arms in a radially outward direction will rock said lever arms upon said tension ring to move the lower ends thereof radially inwardly towards their said closed position.
 26. The tool of claim 23 wherein said control mechanism includes a fluid-operated clutch for selectively disengaging said fluid motor with said nut socket and wherein said cam remains directly connected to said fluid motor.
 27. The tool of claim 26 wherein said clutch includes a movable clutch jaw driven by said fluid motor on an axis parallel with the axis of said nut and cam and movable along said axis from a first position in driving engagement with said nut socket to a second position free of said socket whereby said cam may be driven independently of said socket.
 28. The tool of claim 27 which further includes a fluid control means responsive to torque resistance encountered by said motor driving said socket and effective to shift said clutch plate from its said first to its said second position when said motor encounters a predetermined torque level, thereby stopping rotation of said nut socket and initiating relative rotation of said cam. 